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/* sof.cpp: extracts orbital elements from SOF (Standard Orbit Format)
(See https://www.projectpluto.com/orb_form.htm for an explanation)
Copyright (C) 2018, Project Pluto
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA. */
#include <string.h>
#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include "watdefs.h"
#include "comets.h"
#include "date.h"
int extract_sof_data( ELEMENTS *elem, const char *buff, const char *header);
#define GAUSS_K .01720209895
#define SOLAR_GM (GAUSS_K * GAUSS_K)
#define SOF_Q_FOUND 0x0001
#define SOF_ECC_FOUND 0x0002
#define SOF_NAME_FOUND 0x0004
#define SOF_TPERIH_FOUND 0x0008
#define SOF_TEPOCH_FOUND 0x0010
#define SOF_INCL_FOUND 0x0020
#define SOF_ASC_NODE_FOUND 0x0040
#define SOF_ARG_PERIH_FOUND 0x0080
#define SOF_ABS_MAG_FOUND 0x0100
#define SOF_SLOPE_PARAM_FOUND 0x0200
/* If you don't have these fields, you don't have a defined orbit. */
#define MIN_FIELDS_NEEDED (SOF_Q_FOUND | SOF_ECC_FOUND | SOF_TPERIH_FOUND \
| SOF_INCL_FOUND | SOF_ASC_NODE_FOUND | SOF_ARG_PERIH_FOUND)
/* All dates are currently stored as YYYYMMDD[.dddd], Gregorian. */
static double extract_jd( const char *buff)
{
long t;
int bytes_read;
double rval = 0.;
if( sscanf( buff, "%ld%n", &t, &bytes_read) == 1)
{
if( bytes_read == 8) /* YYYYMMDD */
rval = (double)dmy_to_day( t % 100, (t / 100) % 100, t / 10000,
CALENDAR_GREGORIAN) - .5;
if( buff[bytes_read] == '.')
rval += atof( buff + bytes_read);
}
return( rval);
}
#define PI 3.1415926535897932384626433832795028841971693993751058209749445923
int extract_sof_data( ELEMENTS *elem, const char *buff, const char *header)
{
int fields_found = 0, rval;
memset( elem, 0, sizeof( ELEMENTS));
elem->slope_param = 0.15;
elem->gm = SOLAR_GM;
while( *header >= ' ')
{
size_t i = 0;
while( header[i] >= ' ' && header[i] != '|')
i++;
if( i < 2)
return( -1);
if( header[1] == ' ')
{
switch( header[0])
{
case 'q':
elem->q = atof( buff);
fields_found |= SOF_Q_FOUND;
break;
case 'e':
elem->ecc = atof( buff);
fields_found |= SOF_ECC_FOUND;
break;
case 'i':
elem->incl = atof( buff) * PI / 180.;
fields_found |= SOF_INCL_FOUND;
break;
case 'O':
elem->asc_node = atof( buff) * PI / 180.;
fields_found |= SOF_ASC_NODE_FOUND;
break;
case 'o':
elem->arg_per = atof( buff) * PI / 180.;
fields_found |= SOF_ARG_PERIH_FOUND;
break;
case 'H':
elem->abs_mag = atof( buff);
fields_found |= SOF_ABS_MAG_FOUND;
break;
case 'G':
elem->slope_param = atof( buff);
fields_found |= SOF_SLOPE_PARAM_FOUND;
break;
case 'C':
elem->central_obj = atoi( buff);
break;
}
}
else if( header[2] == ' ')
{
switch( header[0])
{
case 'T':
{
const double jd = extract_jd( buff);
if( header[1] == 'p')
{
elem->perih_time = jd;
fields_found |= SOF_TPERIH_FOUND;
}
else if( header[1] == 'e')
{
elem->epoch = jd;
fields_found |= SOF_TEPOCH_FOUND;
}
elem->q = atof( buff);
fields_found |= SOF_Q_FOUND;
}
break;
case 'O':
elem->asc_node = atof( buff) * PI / 180.;
fields_found |= SOF_ASC_NODE_FOUND;
break;
case 'o':
elem->arg_per = atof( buff) * PI / 180.;
fields_found |= SOF_ARG_PERIH_FOUND;
break;
}
}
if( header[i] == '|')
i++;
header += i;
buff += i;
}
if( (fields_found & MIN_FIELDS_NEEDED) == MIN_FIELDS_NEEDED)
{
rval = 0; /* success */
derive_quantities( elem, elem->gm);
}
else
{
printf( "Got '%x'\n", (unsigned)fields_found);
rval = -1;
}
return( rval);
}
#ifdef TEST_CODE
#define MAX_LEN 300
int main( const int argc, const char **argv)
{
FILE *ifile = fopen( argv[1], "rb");
char header_line[MAX_LEN], buff[MAX_LEN];
char *tptr;
size_t name_len;
assert( ifile);
assert( argc == 3);
if( !fgets( header_line, sizeof( header_line), ifile))
{
printf( "Couldn't read header\n");
return( -1);
}
tptr = strchr( header_line, '|');
assert( tptr);
name_len = tptr - header_line;
while( fgets( buff, sizeof( buff), ifile))
if( (tptr = strstr( buff, argv[2])) && tptr < buff + name_len
&& tptr[strlen( argv[2])] == ' ')
{
ELEMENTS elem;
int rval = extract_sof_data( &elem, buff, header_line);
printf( "rval %d\n", rval);
printf( " Tp= %f\n", elem.perih_time);
printf( " q = %f\n", elem.q);
printf( " a = %f\n", elem.major_axis);
printf( " e = %f\n", elem.ecc);
printf( " H = %f\n", elem.abs_mag);
printf( " i = %f\n", elem.incl * 180. / PI);
printf( " Om= %f\n", elem.asc_node * 180. / PI);
printf( " om= %f\n", elem.arg_per * 180. / PI);
printf( " Epoch = %f\n", elem.epoch);
}
fclose( ifile);
return( 0);
}
#endif
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